Improvement in burglar-alarm looks



@auch gitaren. intent @frn Letters .Patent No. 66,090, dated June 25, 1867.

' IMPROVEMENT IN BRGLAR-ALARM LOCKS.

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TO ALL WHOM IT MAY CONCERN: l

-Be it known that I, GEORGE JACOBS, of `Washington city, District of Columbia, have invented certain new and useful improvements in Burglar-Alarm Locks; and I do hereby declare the following to be a full, true, and Lexact' description of the same, referencerbeing had to the accompanying dra-wings and to the letters of reference `-marked thereon.

Figure 1 represents a plan view of the internal construction of my lock. v

Figure 2 represents a side view of the'setting arrangement with the key used for this purpose.

Figure 3 is a view of one side of the bolt.

Figure 4 is a plan view lof the bolt-attachment. A

Letter A, iigs. 1 and 3, represents the bolt of my lock, which is provided near its inner end with a small u projection for the purpose of catching in the slot in the bolt-attachment B, and also has an opening in one side so as to receive the key and allow'it to be thrown in and out.

Y'Letter B, as shown .in tig. 4; represents the bolt-attachment, bywhich the bolt is prevented from slipping backwards and forwards, and is placed immediately under the Abolt A, as shown in iig.4 1. At its outerend it is perforated for the purpose of allowing it to work upon a pivot, arid is also provided with an elongated spring, so as to give it a reciprocating motion. i At its inner end there is a slot, having two small chambers or recesses, for the purpose of receiving the projecting part of the bolt A. 'As the key is turned to either lock or unlock the door it presses back the device I3V until the bolt is entirely free from the recess, when it moves on to the next one, where it again catches. v l

Letter C, as shown iniiigs. 1 and 2, represents an upright movable pivot, having a coiled spring, c, around its top, and-three projecting arms, of different lengths, vthe uses of which will be fully shown hereafter.

Letter D, as shown in figs. 1 and 2, represents a circular movable plate, whichis pivoted to the outside of the lock, and is perforated in a number of places, for the purpose of confusing and misleading those who do not understand its construction and arrangement. Although thpre are a number of holes inthis plate there is but one of them which is intended to be used, and that one, whenthe plate is in its proper place, shouldbe immel diately over the movable pivot C, so that when the key is inserted into this 'hole it will press the pivot inwards.

Letter E, iig. 2,' represents the key by which the clock-work K is wound. Upon the top or handle of this key is plneeda small upright projection, which is used to set'thealarm;

Letter F reprcsentsa movable pivot, to which is attached Athe double-acting pawl G, and the alarm ham- 'mer H.

l Letter I represents Vthe bell, which is of a scmicircular shape, and upon which ,the hammer H, when in motion, sounds the alarm. Immediately under this bell the frame of the lock is perforated (as shown by .red lines in iig. 1)"in a number of places, so as'to allow the sound to escape more freely.

Letter J represents avcommon door-latch.

The modus operandi of my lock is as follows: The door is first locked; the clock-work K is then wound up bymeans of the key E; the circular plate D isl then turned until the key-hole is immediately under the pivot C, `when the projection upon the handle of tbckey is inserted to its full length, which raises the pivot from its bed far enoughto discngage the lower arm L from theV hole or cavity in the bod of thc lock. Attached to the longest of the three arms is a coiled spring, M, for the purpose of drawing the arms towards the pawl Gr and the bolt A. As soon as the pivot Gfis raised from its position, the coiled spring M drt-.ws the longest arm N around until it rests against the double-acting paw] in such a manner that it prevents it from working-,- and the shortest of the arms O until it rests against the end of the bolt A. Ihe alarm is now set. As soon asl-a personunlocks the door, in turning back the bolt A, it strikes against the arm O and causes the pivot 4to turn backwards, which releases thc pawlG fromthe arm N, when the alarm immediately begins to-sound. After the alarm has once been set in motion it cannot be stopped in any'manner untilthe spring has unwound itself.4 'Ihc coiled spring e, around. the top of the pivot C, then presses downwards until the lower arm L again catches in the frame of the lock, when it is ready to be wound up again.

Having thus fully described my invention, what I claim, and desire to secure by Lctterslatent, isy 1. The employment of arms L N O, for the purpose-of holding and letting olf the alarm arrangement, substantially in the manner set fort-h.

2. In combination with the above I claim the sliding pivot C and spring P, substantially as set forthV and for the purposes described.

'lhc circular` plate D, provided with deceptive holes, in combination with arms L N O, operating substantially as specified.

4. I claim the arrangement of bolt A, arms L N O, spring M, sliding pivot C. and plate D, substantially j for the purpose described.

. In testimony whereof I'set my signature iny presence of two witnesses.

GEORGE JACOBS. Witnesses:

T. H. ALEXANDER, F. A. LEHMANN. 

